I went to Circuit City and asked them if they had the power line noise supressor/filter. THey said that they had no idea what i was talking about. they siad the only noise supressor is the groundloop isolator. Is it me or should they know what I am talking about? To me it should be pretty common knowledge if you are an installer what the power line noise filter is ...or am i wrong?

i also doubt their install knowledge because i got 2 dual 4ohm subs, they tried to explain to me that i had to get a new amp since they wont work with my amp since they are dual coils...but i wired them so they have 8 ohm each and wired them in parallel so its 4ohm, where my amp puts out the max power. this was on a different daywhen i bought new subs from circuit city.

to make al ong story short, its the power like spuressor that i need, its not a groundloop or anything like that so the groundloop isolators that the people at CC suggested is worhtless in my case



Modified by imadigitalgod at 8:23 PM 6/13/2006

 

You have to keep in mind that they are out to make commission on their sales. You cant really blame them for trying to make money but they are wrong. You dont need a different amp. How you wired your subs is the way I would have done it. Why buy an amp if you can match the impedence? As far as the power line noise surpressor I have an Alpine one in my car as well as a ground loop isolator. If you can use bothh for best results.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SiRGDC &raquo;</TD></TR><TR><TD CLASS="quote">You have to keep in mind that they are out to make commission on their sales. You cant really blame them for trying to make money but they are wrong. You dont need a different amp. How you wired your subs is the way I would have done it. Why buy an amp if you can match the impedence? As far as the power line noise surpressor I have an Alpine one in my car as well as a ground loop isolator. If you can use bothh for best results. </TD></TR></TABLE>

the circuit city i went to doesnt make commission on their sales...he was just telling me htat i needed a new amp for my benifit...or he thought. i knew he was wrong when he said that suff tho. i just didnt want to explain to him that he was wrong in what he was saying because i took my subs back because one of them were blown so i took both of them back...if i explained to him that i know all about wiring things up correctly then they probably would have checked both subs to see if they were blown.

as for the ground loop isolator, the way the amp is made, its only the power line thats the problem. right now there is just an 8ohm speaker out of an alarm clock running off of the microphone amp so theres no groundloop that could be since its just that speaker running off of the microphone amp. when i did hookup my voltage regulator it did cut the noise 95%....idk if u knew but the opamps that run the preouts on the headunits are powered by voltage regulators. it drops the voltage that is supplied to have it below the "line"(as if it were on a graph or oaciloscope) that has the engine noise in it.

the regulator isnt powerful enough to power my electret microphone(has to be externally powered, its not self powered)and the LM386 mic amp at the same time.

But still, shouldnt the installers at circuit city that get paid to install peoples audio equiptment have to atleast HEARD of the power line suppressor/filter? they siad they hadnt even heard of anything like that.

 

Your right on both counts, the sales man was wrong, [obviously you did not need an amp] and even he should have known what a power line noise suppressor was and the installer definitely should have, [what I see is less then experienced staff] although power line noise suppressors, [line choke] are not used much anymore although you can still get them... http://www.scosche.com/scosche...ES004
or these... http://www.installer-data.com/...pdf30

I am not sure exactly where you want to install one, ["microphone amp"?] but they do still exist. 94

 

I went to a shop today that only deals with audio stuff (Santa Fe Autosound in Overland Park, Kansas) and they knew what i needed right off the bat and gotit for me. At circuit city I was very saddened by that it wasnt the salesmen that didnt know what it was, it was the actual installers that i was asking. the first person i asked didnt know what i was taking about so he asked the manager of the shop at the time and he didnt know either I could have built one easily, i just didnt know where to get a 3-4mH inductor in town. i found them easily off of the net but didnt want to wait. the one i got was only $8 so im happy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote">I am not sure exactly where you want to install one, ["microphone amp"?] but they do still exist. 94 </TD></TR></TABLE>

lol well long story short i made an amp and a different circuit (and installed a plugin in my car that is hidden inside the cubby hole infront of my shifter so its hidden) so that it allows me to have a PA system in my car.

I installed relays on the + side of each speaker inside. i also put a wire thats bridged across my front speaker amp that is also hooked to a relay(only the bridged wire at that point, not the amp). the inside speakers(and the sub remote turnon wire) is hooked to SPDT relays, all on the 87a(normally closed) part of the relay and the wire that is bridged on my front speaker amp is connected to the normally open(87). when the power is put to all the relays, the inside speakers turn off and the wire that is bridged to the amp gets 'turned on'(closed circuit for that wire, open for all the other ones). to that wire i have a loudspeaker i installed under my intake in my engine bay. this allows music to play outside outloud so when im working under the car or anything outside i can listen to the music(i have it bridged so i get both ch. instead of just one.)

anyways, when i put it to AUX on my cd player, the mic preamp will play through the cd player, which goes to the external amp, which plays through the speaker under the hood. the mic preamp that i had made pics up the engine noise through the power line so this should fix that when i get it hooked up later on tonight The relays i had in place is so 1, theres no wasted power playing the music through the inside speakers, and 2.) impedence issues with running speakers off of each ch but also havin that one bridged across both ch. once the relays are on, it basically disconnects the front speakers from the amp(also the rear speakers that are off of the head unit) so its like the only thing the amp is powering is that bridged 8ohm speaker

I modded the power line filter tho,i added a capacitor on the power source side of the filter so it had one cap on each side of the inductor inside...that should make itwork better

 

it sounds messy but if u look at the inside of my car, it looks 100% stock, unmessed with, well except for the cd player of course

 

OIC, I think...... 94

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote">OIC, I think...... 94</TD></TR></TABLE>

lol well to sum it up, when i flip one switch, it cuts off all the speakers and my subs inside, turns on the loudspeaker under my hood and plays whatever music was playing inside my car. if i turn my microphone preamp that i made, then i can talk through my mic inside and it will play though the loudspeaker outside(the cd player has to b on 'aux' forthe mic amp to work tho).

Kind of a dumb idea but i was bored one day and wanted to do something, so i used my extra parts that i had and made this.

 

Well, awesomeness...there is 100% reduction in the engine noise after i installed the line choke for my amp that i made. im goin to go solder everything inside my dash since it seems to work 'on the bench" testing(or trunk testing is what i did).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by imadigitalgod &raquo;</TD></TR><TR><TD CLASS="quote">

lol well to sum it up, when i flip one switch, it cuts off all the speakers and my subs inside, turns on the loudspeaker under my hood and plays whatever music was playing inside my car. if i turn my microphone preamp that i made, then i can talk through my mic inside and it will play though the loudspeaker outside(the cd player has to b on 'aux' forthe mic amp to work tho).

Kind of a dumb idea but i was bored one day and wanted to do something, so i used my extra parts that i had and made this. </TD></TR></TABLE> OIC, now I get it, like a radio/tape deck switch, [lets you use two sources with one set of speakers] but reversed one source and two sets of speakers, [speakers and PA horn].

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by imadigitalgod &raquo;</TD></TR><TR><TD CLASS="quote">Well, awesomeness...there is 100% reduction in the engine noise after i installed the line choke for my amp that i made. im goin to go solder everything inside my dash since it seems to work 'on the bench" testing(or trunk testing is what i did). </TD></TR></TABLE> always good to hear something works. 94

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote"> [speakers and PA horn]. </TD></TR></TABLE>

yep